1. Field of the Invention
The present invention relates to an apparatus and method for transporting solid waste materials. The apparatus and method are particularly, but not exclusively, for transporting drill cuttings and other waste resulting from the drilling of a borehole or a tunnel.
2. Description of Related Art
A drill bit arranged on the end of a drill pipe string is used to drill a borehole or tunnel in the formation of an oil or gas well or the like. A drilling fluid known as ôdrilling mudö is pumped through the drill string to the drill bit to lubricate the drill bit. The drilling mud is also used to carry the cuttings produced by the drill bit to the surface through the annulus formed between the drill string and the borehole or tunnel. The drilling mud contains expensive synthetic oil-based lubricants and it is normal therefore to recover the used drilling mud, but this requires the cuttings to be removed from the drilling mud. Typically this is achieved by processing the drilling fluid with a vibratory screening machine (e.g. of the type disclosed in U.S. Pat. No. 5,265,730 or WO 98/16328), which separates the cuttings from the drilling fluid.
In the past, on oil platforms out at sea, such cuttings were simply thrown overboard but this practice has been discontinued, as being environmentally damaging. It is known to pass the recovered cuttings into a ôditchö (i.e. a duct or channel), from which the cuttings are removed by the application of suction from a vacuum hose, the cuttings being transported along the vacuum hose and deposited in a collection hopper. Such a method is labour intensive, typically requiring three people to perform the operation: one person to guide the hose along the ditch, one to monitor the collection hopper, and a third person to clear any blockages in the hose.